In known doctoring apparatus, a doctor blade has a working edge that is applied to a rotating surface of an elongated cylinder. The working edge of the doctor blade removes materials from the rotating surface of the cylinder. The doctored materials to be removed may consist of a sheet or web being processed in a papermaking machine, or the doctored material may consist of contaminates accumulating on the surface of the cylinder.
Doctoring apparatus typically comprise a blade carrier assembly which is adapted to hold the doctor blade in operative engagement with the surface of the rotating cylinder to be doctored. The blade carrier assembly is mounted about a pivoting axis where the angle of the blade and pressure associated with the blade contacting the surface is controlled by two flexible walled tubes located on either side of the pivoting axis. The blade carrier assembly is mounted directly to a doctor back and the doctor back is positioned within the papermaking machine across the width of the cylindrical surface to be doctored. In some instances, the doctoring apparatus extends from 3 to 8 meters in width across a cylindrical roll.
The doctor blade is removably mounted in the blade carrier assembly. This permits the removal of the doctor blade for cleaning. However, maintenance of the blade carrier assembly is not as simple because it is not possible to remove the blade carrier assembly from the doctor back. Thus maintenance of the blade carrier assembly requires having to maintain the blade carrier assembly from within the machine which is difficult and cumbersome.